diff --git a/.travis.yml b/.travis.yml
index 2dcac0f4..5524bce5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,10 +4,33 @@
 #    packages:
 #      - oracle-java8-installer
 language: scala
+scala:
+  - 2.11.12
+  - 2.12.5
+  - 2.13.0-pre-b11db01
 jdk:
   - oraclejdk8
+env:
+  - SCALAJS_VERSION=
+  - SCALAJS_VERSION=0.6.22
+  - SCALAJS_VERSION=1.0.0-M3
+matrix:
+  exclude:
+    - scala: 2.13.0-pre-b11db01
+      env: SCALAJS_VERSION=0.6.22
+    - scala: 2.13.0-pre-b11db01
+      env: SCALAJS_VERSION=1.0.0-M3
+  include:
+    - scala: 2.12.5
+      env: TEST_SCALAFIX=true
 before_script:
   - ./checkCLA.sh
 script:
-  - sbt +test
-  - cd scalafix && sbt input/compile output/compile tests/test
+  - |
+    if [[ $TEST_SCALAFIX == "true" ]]; then
+      cd scalafix && sbt input/compile output/compile tests/test
+    elif [[ $SCALAJS_VERSION == "" ]]; then
+      sbt ++$TRAVIS_SCALA_VERSION scala-collection-compat/test
+    else
+      sbt ++$TRAVIS_SCALA_VERSION scala-collection-compatJS/test
+    fi
diff --git a/build.sbt b/build.sbt
index a7e598cf..d08ec76b 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,18 +1,29 @@
-organization := "org.scala-lang"
+import sbtcrossproject.{crossProject, CrossType}
 
-name := "scala-collection-compat"
+inThisBuild(Def.settings(
+  organization := "org.scala-lang",
+  version := "0.1-SNAPSHOT",
+  resolvers += "scala-pr" at "https://scala-ci.typesafe.com/artifactory/scala-integration/",
+  crossScalaVersions := Seq("2.12.5", "2.13.0-pre-b11db01", "2.11.12"),
+  scalaVersion := crossScalaVersions.value.head
+))
 
-version := "0.1-SNAPSHOT"
+lazy val `scala-collection-compat` = crossProject(JSPlatform, JVMPlatform)
+  .withoutSuffixFor(JVMPlatform)
+  .crossType(CrossType.Pure)
+  .in(file("."))
+  .settings(
+    name := "scala-collection-compat",
+    unmanagedSourceDirectories in Compile += {
+      val sharedSourceDir = baseDirectory.value.getParentFile / "src/main"
+      if (scalaVersion.value.startsWith("2.13.")) sharedSourceDir / "scala-2.13"
+      else sharedSourceDir / "scala-2.11_2.12"
+    }
+  )
+  .jvmSettings(
+    libraryDependencies += "com.novocode" % "junit-interface" % "0.11" % "test"
+  )
+  .jsConfigure(_.enablePlugins(ScalaJSJUnitPlugin))
 
-resolvers += "scala-pr" at "https://scala-ci.typesafe.com/artifactory/scala-integration/"
-
-unmanagedSourceDirectories in Compile += (
-  if(scalaVersion.value.startsWith("2.13.")) (sourceDirectory in Compile).value / "scala-2.13"
-  else (sourceDirectory in Compile).value / "scala-2.11_2.12"
-)
-
-crossScalaVersions := Seq("2.12.5", "2.13.0-pre-b11db01", "2.11.12")
-
-scalaVersion := crossScalaVersions.value.head
-
-libraryDependencies += "com.novocode" % "junit-interface" % "0.11" % "test"
+lazy val `scala-collection-compatJVM` = `scala-collection-compat`.jvm
+lazy val `scala-collection-compatJS` = `scala-collection-compat`.js
diff --git a/project/plugins.sbt b/project/plugins.sbt
new file mode 100644
index 00000000..3c396380
--- /dev/null
+++ b/project/plugins.sbt
@@ -0,0 +1,5 @@
+val scalaJSVersion =
+  Option(System.getenv("SCALAJS_VERSION")).filter(_.nonEmpty).getOrElse("0.6.22")
+
+addSbtPlugin("org.scala-js" % "sbt-scalajs" % scalaJSVersion)
+addSbtPlugin("org.portable-scala" % "sbt-scalajs-crossproject" % "0.4.0")